Diet soda, Twinkies, and the Questions that Matter

Good Enough Exercise

I’m joined by Dr. Jeffrey Sankoff to talk about three exercise “rules” you may be allowed to break: you don’t always need to spread workouts across the week, intensity doesn’t have to come from a formal interval session, and most short workouts don’t require a complicated hydration or fueling plan. The Exercise Rules You’re Allowed to Break Have you ever skipped a workout because you couldn’t do the “right” one? Maybe you didn’t have time for the gym, a long hike, or a structured bike ride. Today, we revisit Voltaire’s reminder that “the great is the enemy of the good” and apply it to exercise. The evidence is reassuring: weekend workouts count, short bursts of effort during the day count, and for most workouts under an hour, hydration hype may matter far less than we’ve been led to believe. Dr. Jeffrey Sankoff, an ER physician, Ironman triathlete, triathlon coach, and host of the evidence-focused TriDoc Podcast, joins me for this conversation. While Jeff works with endurance athletes, today’s discussion is for anyone who wants to live long and well while still managing the realities of work, family, travel, and everyday life. First, we break the calendar rule. Many people assume exercise has to be spread evenly throughout the week, but a 2024 Circulation study on “weekend warrior” physical activity found that people who concentrated their moderate-to-vigorous exercise into one or two days still had lower risk for many diseases compared with inactive people, especially cardiometabolic conditions such as hypertension, diabetes, obesity, and sleep apnea. The study was observational, so it does not prove weekend-only exercise is ideal, and injury risk still matters. But the practical message is clear: if weekdays are impossible, weekends still count.  Next, we break the formal-interval rule. High intensity does not always have to mean a structured HIIT class, a bike trainer, or a carefully timed workout. A 2026 European Heart Journal study found that a higher percentage of vigorous physical activity was associated with lower risk across several chronic diseases and mortality outcomes. Even a small proportion of vigorous activity may matter, meaning short real-life bursts—taking the stairs quickly, walking briskly uphill, carrying groceries with purpose, or chasing a child or grandchild—can become meaningful movement when they raise your breathing and effort level. This study was also observational, so it cannot prove cause and effect, and anyone with medical concerns should check with their clinician before adding vigorous bursts.  Finally, we break the bottle rule. For endurance races, long workouts, or hot-weather exercise, hydration, electrolytes, and carbohydrates can matter. But for many 30- to 60-minute workouts in ordinary conditions, a formal hydration or fueling plan may not be necessary. The American College of Sports Medicine’s position stand emphasizes fluid replacement to support hydration during physical activity, but the need depends on duration, sweat loss, heat, and intensity. A practical “N of 1” approach is to weigh yourself before and after a typical workout to see how much fluid you actually lose.  We also discuss electrolytes and carbohydrates. Electrolytes are mostly salts, and they become more relevant with long, hot, sweaty, or repeated sessions. Carbohydrate-containing drinks can help with longer endurance performance, but for a 35-minute walk or a short gym session, sugar in your bottle is usually not the bottleneck. A systematic review on carbohydrates and exercise performance found benefits in longer exercise contexts, but that does not mean every short workout needs sports drinks or gels.  Takeaways Don’t let the perfect workout plan keep you from the good-enough workout you can actually do. If weekdays are packed, a weekend warrior approach may still provide meaningful health benefits. Look for small bursts of vigorous effort in daily life, and for most workouts under an hour, water when thirsty is usually enough. Send us Fan Mail [https://www.buzzsprout.com/2297572/fan_mail/new] Support the show [https://drbobbylivelongandwell.com] > 📥 Tap to join my free newsletter & get the 1-page episode checklists: drbobbylivelongandwell.com [https://drbobbylivelongandwell.com/]

Longevity Summarized: The Compass, the Detour, and the Parking Brake

After 70 episodes, I've noticed a pattern that keeps showing up in every corner of longevity, wellness, and medicine: people don’t fail because they “don’t care.” They fail because the signal is buried under hype, and because perfectionism makes the basics feel impossible to sustain. So I step back and share a simple framework  for living long and well: treat evidence like a compass, treat hype like a detour, and treat perfectionism like a parking brake. I walk through how to read health evidence without getting lost. Randomized controlled trials vs observational studies, replication, meta-analyses, and the most important filter of all: are we looking at meaningful outcomes like fewer heart attacks, better function, clearer thinking, and longer life, or are we just watching biomarkers move. We also revisit how research in stable coronary artery disease forced a shift away from the intuitive “fix the plumbing” story and back toward the unglamorous risk factors that actually drive health. Then we get practical about what to do when averages don’t map cleanly onto you. Using sleep and melatonin as an example, we explain a careful N-of-1 approach, including the power of stopping and restarting so you can tell whether a change truly helps. From there, we break down the “hype equation” using mitochondrial health and NAD claims to show how plausible mechanisms, credentials, anecdotes, and incentives can make weak evidence feel strong. Finally, we make the case for “good enough” health: the 80-20 moves that deliver most of the benefit, plus the mindset that leaves room for joy. If this helps, subscribe, share it with a friend who’s tired of wellness noise, and leave a review so more people can find the compass. Send us Fan Mail [https://www.buzzsprout.com/2297572/fan_mail/new] Support the show [https://drbobbylivelongandwell.com] > 📥 Tap to join my free newsletter & get the 1-page episode checklists: drbobbylivelongandwell.com [https://drbobbylivelongandwell.com/]

Diet soda, Twinkies, and the Questions that Matter

Episode Summary: In this episode, I look at diet soda, artificial sweeteners, and the real-world question that matters most: compared with what, at what dose, for whom, and at what tradeoff? Diet Coke, Twinkies, and the Questions That Matter I start with a memory from medical training: a cardiology professor walking around with a Diet Coke in one hand and a Twinkie in his pocket. Was he making a smart tradeoff, or fooling himself? That image captures the artificial sweetener debate well. A diet soda may be a useful substitute if it replaces a sugary drink, but it becomes less compelling if it simply gives us permission to eat more ultra-processed foods. The cleanest case for artificial sweeteners is substitution. In the CHOICE trial, adults who replaced caloric beverages with water or diet drinks lost a modest amount of weight over six months, suggesting that noncaloric beverages can help when they replace sugar-sweetened drinks.  The SWITCH trial similarly found that people assigned to non-nutritive sweetened beverages did at least as well as those assigned to water after a 52-week weight management program.  I also explore the common fears around artificial sweeteners. The cancer concern has roots in older animal studies involving very high doses, but the National Cancer Institute notes that the saccharin bladder cancer mechanism seen in rats does not apply to humans, and saccharin was removed from the U.S. carcinogen list in 2000.  A large French observational study, NutriNet-Santé, did find a small association between artificial sweetener intake and cancer risk, especially aspartame and acesulfame-K, but observational studies can’t prove causation and are vulnerable to residual confounding.  On weight gain and glucose metabolism, the evidence is less alarming than the headlines. Randomized trials do not support the idea that diet soda inevitably causes weight gain. And in the SODAS trial, replacing artificially sweetened beverages with water in adults with type 2 diabetes did not improve glycemic measures, which weakens the claim that diet drinks secretly worsen blood sugar control.  The microbiome question is interesting but not settled. A well-known 2014 study suggested artificial sweeteners could alter the gut microbiome and glucose tolerance, but much of that evidence came from mice and a very small human experiment.  More recently, the SWEET study found that sweeteners and sweetness enhancers, when used within a healthy diet, supported weight-loss maintenance and were linked with beneficial gut microbiome shifts in adults with overweight or obesity.  The real issue may not be whether Diet Coke is “good” or “bad.” Water wins the purity contest. But food and drink also provide pleasure, ritual, and sustainability. If a diet soda helps someone avoid sugar and enjoy lunch, that may be a reasonable bargain. But if it becomes a permission slip for a daily Twinkie, we should pay attention. Ultra-processed foods matter because in a controlled feeding study, people ate about 500 more calories per day when eating an ultra-processed diet.  Takeaways Ask the better question: not “Is diet soda good or bad?” but “Compared with what, at what dose, for whom, and at what tradeoff?” Artificial sweeteners appear most useful when they replace sugar-sweetened drinks, and less useful when they replace water. Diet soda may be a reasonable pleasure for many people, but it is worth noticing whether it helps reduce sugar—or simply makes the Twinkie in your pocket easier to justify. Send us Fan Mail [https://www.buzzsprout.com/2297572/fan_mail/new] Support the show [https://drbobbylivelongandwell.com] > 📥 Tap to join my free newsletter & get the 1-page episode checklists: drbobbylivelongandwell.com [https://drbobbylivelongandwell.com/]

What’s Wrong With Me?” What AI Gets Right — And What It Gets Really Wrong

In this episode, I explore where AI can genuinely help with health questions, where it can fall dangerously short, and how to use it more wisely before trusting it with decisions that really matter. AI tools like ChatGPT, Claude, Grok, and Gemini can be useful for understanding lab results, summarizing a doctor’s visit, preparing questions before an appointment, or making sense of complicated medical language. But when people ask AI, “What’s wrong with me?” or “Should I go to the hospital?” the answer can depend heavily on whether the user provides enough clinical context. I tested this myself with two invented scenarios: hand pain and a concerning headache. In both cases, the AI gave general guidance but failed to ask key questions a physician would naturally ask, such as my age, whether symptoms came on suddenly, whether I had experienced this before, or whether there was relevant family history. When I explicitly asked the AI to interview me first, the answers improved dramatically. Research supports that concern. A recent Nature Medicine study [https://www.nature.com/articles/s41591-025-04074-y] found that when real users interacted with AI about clinical scenarios, the AI gave the correct triage recommendation in only about 43% of cases and often underestimated urgency. The problem was not always that AI lacked medical knowledge. It was that users often did not provide enough information, and the AI did not reliably ask for what it needed. Another Nature Medicine study [https://www.nature.com/articles/s41591-026-04297-7] tested ChatGPT Health using complete clinical vignettes. Even with all the information provided, the AI struggled with the most urgent and least urgent cases. It sometimes recognized serious diagnoses but recommended delayed care when immediate emergency care was appropriate. That suggests the issue is not just knowledge, but judgment. AI does perform better in lower-risk, supportive roles. It can translate medical jargon into plain language, explain abnormal lab results, organize a visit summary, and help patients prepare better questions for their doctor. Recording a medical visit with the doctor’s permission and then using AI to create a personal summary can be especially helpful, though AI-generated clinical notes still need careful physician review. The most practical strategy is simple: before asking AI for health guidance, tell it, “Before you respond, please ask me all the questions you need to give me accurate information about my situation.” This does not make AI a doctor, but it can make the interaction more useful and less incomplete. Takeaways: AI can be helpful for understanding, organizing, and preparing for healthcare conversations, especially when the stakes are relatively low. AI is not yet reliable enough to determine whether symptoms are urgent or whether you should go to the ER. When using AI for health questions, ask it to interview you first, and when symptoms feel serious, unusual, sudden, or frightening, do not rely on AI as your final decision-maker. Send us Fan Mail [https://www.buzzsprout.com/2297572/fan_mail/new] Support the show [https://drbobbylivelongandwell.com] > 📥 Tap to join my free newsletter & get the 1-page episode checklists: drbobbylivelongandwell.com [https://drbobbylivelongandwell.com/]

#69 Being Happy: Physiology Often Beats Insight

In this episode, I explore a difficult but important idea: when it comes to depression, anxiety, fear, and emotional suffering, changing physiology often works better than understanding the story behind the pain.  I begin with a simple question: why do we assume insight should heal us? As human beings, we naturally look for patterns and explanations, but explanation is not the same as relief. I share two personal examples—my years of dysthymia that lifted quickly with Wellbutrin, and my exercise-related fears that insight alone never resolved—to show how biology can sometimes succeed where understanding falls short. From there, I look at everyday examples that make this idea easier to grasp. A bad night of sleep can worsen emotional balance, while a good night of sleep can make the world feel more manageable again. Likewise, structured breathwork can calm the body and improve mood, suggesting that sometimes the body changes first and the mind follows. Sleep-loss review [https://pubmed.ncbi.nlm.nih.gov/38127505/?utm_source=chatgpt.com] and breathwork trial [https://pubmed.ncbi.nlm.nih.gov/36630953/?utm_source=chatgpt.com] are two examples I discuss.  I then turn to more dramatic examples in mental health treatment. ECT [https://pubmed.ncbi.nlm.nih.gov/12642045/?utm_source=chatgpt.com] can improve severe depression without requiring a better narrative about the past, and vagus nerve stimulation [https://pubmed.ncbi.nlm.nih.gov/41106630/?utm_source=chatgpt.com] offers another reminder that mood is also a biological state. I also touch on emerging research around psilocybin and neuroplasticity [https://pubmed.ncbi.nlm.nih.gov/40957728/?utm_source=chatgpt.com] , while emphasizing that this area remains early and experimental.  Finally, I explore therapies that work not by increasing insight, but by retraining the nervous system. Exposure-based approaches can reduce fear through repeated safe contact with what scares us, and I discuss why I’m personally experimenting with EMDR as a way to loosen the connection between exertion and fear. My goal is not to dismiss therapy, but to make a clearer distinction: insight can be meaningful, but it does not always reduce suffering. Sometimes the nervous system needs calming, retraining, or direct biological support.  Takeaways If understanding your sadness, anxiety, or fear has not brought relief, it may be worth exploring approaches that target sleep, breathing, body state, or brain physiology directly. Don’t confuse explanation with treatment. And remember: sometimes the path to feeling better begins not with a better story, but with a different state.  Send us Fan Mail [https://www.buzzsprout.com/2297572/fan_mail/new] Support the show [https://drbobbylivelongandwell.com] > 📥 Tap to join my free newsletter & get the 1-page episode checklists: drbobbylivelongandwell.com [https://drbobbylivelongandwell.com/]